1. Field of the Invention
The present invention relates to a vertical interconnect structure, a memory device and an associated production method.
2. Description of Related Art
For the formation of integrated semiconductor circuits, a multiplicity of interconnect structures are required for realizing a wiring or for connecting the semiconductor components formed in the semiconductor substrate. On the one hand, these are horizontal interconnect structures that are formed essentially in metallization planes lying above a semiconductor substrate and are isolated from one another by dielectric layers lying in between. Furthermore, vertical interconnect structures are required, which either enable a contact-connection from a first interconnect or metallization plane to the underlying semiconductor substrate and are usually referred to as contacts or, in superordinate metallization planes or interconnect planes, provide for a connection between said interconnect planes and are usually referred to as contact vias.
Particularly in semiconductor memory devices having volatile or nonvolatile memory elements, a high integration density is necessary in order to realize a maximum number of items of information per unit area. Furthermore, the production costs are of particular importance for commercialization.
Usually, in order to realize such vertical interconnect structures or contacts or contact vias, by means of photolithographic methods, contact holes or openings are formed in the dielectric layers and the contact holes are subsequently filled with electrically conductive filling material. The very high production costs and also the minimum feature sizes which can be realized only to a limited extent, which prevent more extensive integration, are disadvantageous in this case in particular on account of the photolithographic method. Accordingly, there is a need for an improved vertical interconnect structure, memory device and associated methods of production.